Wall covering material for use in space heating



United States Patent Bullet 950 Mossin n e h 0 C 6 5 9 [72] Inventor [22] Filed .W n nn o S Wm WWW mua Q m 8 m n D. n mm m n w Es mk it n m mW m 2W 7 mm 1 no nn PA May 26, 1965, Pat. No. 3,473 [45] Patented [54] WALL COVERING MATERIAL FOR USE IN SPACE ABSTRACT: A multilayer wall covering material for use in HEATING space heating by means of an electric resistance heating film g Chimsg Drawing Figs sandwiched between two other layers is a rollable structure (produced at latest when applied to a wall) comprising a three US. Cl.....-.............--.-.--...-----....---...-........... ti structure- Th fi section incorporates the Sand- 219/213,219/528,219/549 wic h, the second is an adhesive surface, and the third section In. cl.-..n-n-n.." .-........-.-...--nun-"nun"... is on the pace side of the first The adhesion' constituting the 0fSearch............................................ second ection can be sufficiently weakened an externally applied agent e.g. heat or a solvent to enable the third section to be stripped without damaging the first. The third section is penetrable by the agent, the first section is undamaged it suffices for the layer of the S m T m N .m m H M .m "P m mm m 1 "a 0 T mmm n S yelnn a u eo.mau h wRBEHDWC 0478l74 N5566335 9999999 1111111. 6 17266 1 thereby; in the case of a solvent third section adjacent to the second section to be impenetrable to the solvent. The material may include two surfaces weakenable by different agents. It may also incorporate two heating films, a heat reflector layer, various kinds of thermal insulation, be flexible so that it can be rolled up, or have an inflatable rear layer so that the spacing of the film from the wall can be varied.

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sum 2 0F 3 78 g a a i PATENTEU DEC 8 I970 SHEET 3 OF 3 FIG-L3. F164 INVINTQQ hwvoeNaY WALL COVERING MATERIAL FOR USE IN SPACE HEATING This application is a continuation-in-part of my application Ser. No. 458,914 filed May 26, 1965 now US. Pat. No. 3,473,003. 1

This invention relates to 'a rollable multilayer covering material for use in space heating which includes an electric resistance heating film betweenat least two other flexible layers. An electric resistance heating film is a thin flexible structure which presents an electrically resistant path between terminal areas at which connection is made to it from a supply. The path desirably comprises a plurality of meander paths in parallel which can be produced by forming sequences of parallel slots in two relatively staggered sets in a thin conductive material such as a metal foil, or it may consist of a multitude of parallel paths in a sheet material, having a conductive coating, for example of carbon or graphite; usually the conductive material, which is desirably crimped, is held to a thin flexible layer or between two such layers and these may be provided with external metallic foil coverings so that the film is itself a multilayer structure but for the purposes of the present invention the film may be regarded as one of the constituent layers of the rollable multilayer covering material. Examples of such heating films are described in my US. Pat. Nos. 2,971,073, 3,020,378, 3,149,406, 3,283,284 and 3,317,657.

4 Such a film when energized in general dissipates heat equally in opposite directions from its two surfaces and when used in a wall covering, some heat will be dissipated into the space bounded by the wall and some into the wall itself. The relative rates of dissipation can be predetermined at least to some extent by choice of the other layers of the material which come between the film and the space and between the film and the wall but this does not allow for regulation of the relative rates during operation.

The invention providesfor this by the provision of a rollable multilayer-material comprising two electric resistance heating ice of which film is energized and by the choice of the relative rates of supply if both are energized at the same time. Ad-

vantageous the two films are so connected when in use that they can be independently controlled for dissipating heat into the space under conditions which can be adjusted differently in respect of at least one of the factors of timing, distribution of energy over the area bounding the enclosed space, amount of energy and manner of dissipation. The layers of the material may be laminated together either at the time of application to the wall or at some previous stage so that the multilayer material would be prefabricated or partly prefabricated. For example there may need to be a layer of thermal insulation between the heating film and the mass of the wall and a decorative layer on the side of the heating film towards the space; it may also be necessary to include within the multilayer material a thermal radiation reflecting layer. It also may be necessary from time to time to replace one of the layers, for example a decorative layer or the heating film, while the underlying layers may still be perfectly satisfactory if they can only be left undamaged.

To this end the material may comprise at least three sections, the second section being a thin layer having two surfaces at which the first section and thethird section respectively are normally adhered thereto, neither heating film forming a part of the second section, the third section consisting of all the layers on the space side of the second section, the adhesion afforded by the second sectionbeing weakenable by an externally applicable agent sufficiently to enable delamination to be effected thereat between the first section and the third section without damage to the first section, the first sect'lbn being undamaged by said agent, and the third section being penetrable by said agent.

Since neither film is part of the second section, delamination can be effected without damage to the films. Also the thin layer constituting the second section will usually be very thin, being no more than a coating of adhesive so that when delamination is effected the whole-layer will be broken down. It is therefore convenient to refer to this layer as a zone or even merely as a surface.

The rollable nature of the material of the present invention means that is is produced from layers that are themselves rollable and can therefore be drawn from the roll in producing the multilayer material, and that the latter can also be stored in the roll which makes for great advantage in storage and in handling.

The particular two layers between which the delamination can be effected in the above manner will be chosen according to the particular type of installation in which the multilayer material is used. For example, a common requirement may be the possibility of stripping a decorative layer such as wallpaper so leaving all the underlying layers intact. In other cases it may be more important to be able to strip the heating films together with such layers as overlie it without damaging the underlying layers.

The zone of adhesion at which delamination is permitted may be formed by an adhesive which can be weakened by an agent which will penetrate the layers to be delaminated and is used in stripping said layers, while the underlying layer and its adhesion to the layers nearer the wall are resistant to said to be effected at two (or even more) interlayer zones of material, for example to enable either a decorative layer to be stripped from the underlying layers or the heating film with the decorative layer and any intermediate layers to be stripped, in which case the adhesion of the various layers to one another at the two zones in question could be of such character as to permit stripping at either of them, independently of the other or both together, by suitable choice of the adhesive and the agent used in stripping.

The invention will be further described with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a cross section of a first example of embodiment of the invention;

FIG. 2 is a circuit diagram illustrating one mode of control of the material shown in FIG. 1;

FIGS. 3 and 4 are side views of another example of embodiment of the invention, respectively in a position but of use and a position in use;

FIGS. 5 and 6 are a side view with part broken away and a cross section of a third example in two different positions of adjustment;

FIG. 5a is a circuit diagram; and

FIG. 7 is a face view with part broken away showing a typical example of a patterned foil used in the heating film.

Referring now to FIG. 1, this illustrates a rollable multilayer material which incorporates two heating films and it is shown secured to a wall. Mounted directly on the wall 76 is a relatively thin flexible thermal insulating layer 77. Mounted on this layer is a heating film 78 comprising a patterned foil 79 sandwiched between two layers of flexible insulating paper 81, 82. Mounted on the heating film 78 is a relatively thick flexible thermal insulating layer 83 of a material which is easily dentable on which is mounted a flexible layer 80 which is substantially more resistant to denting and protects the layer 83 from being dented. This layer 80 is desirably of a material which is of substantially higher density then the layer 83 and has an extensibility less than the maximum extensibility of a second D film 84, and is in widths 73, 74., 75 etc. which are disposed overlapping along the edges as at 70, so that when heated the material can expand and can subsequently contract on cooling without visible gaps being produced between adjacent width of wallpaper, such as might occur if the widths were hung abutted and spoil the appearance of the decorated wall.

The relatively thick insulating layer 83 may be formed of foamed or expanded synthetic resin materials, i.e. porous materials, or of corrugated paper, or any such material having a high air/solid ratio and thus forming a good insulator. The less easily dentable layer 80 may be of metallic foil. Such a foil can at the same time act as a thermally reflecting layer. In some cases such a layer may constitute the surface layer i.e. the wallpaper might be omitted. In other cases the wallpaper itself may constitute a thermally reflecting layer, being for instance ofa very light colour. Or again, if the patterned foils 71, 72 etc. are of suitable character and the pattern itself does not result in large gaps in the foils, these can act as a thermally reflecting layer. A typical pattern such as shown in FIG. 7, in which there are narrow lozenge-shaped slots 101 in a sheet of foil 102, leaves a sufficient area of the foil unbroken for it to serve satisfactorily as a thermally reflecting layer in some cases. If other provision for a thermally reflecting layer is made, the less easily dentable layer 80 instead of being of metal foil, can be of a high density strong polymer foil, e.g. Melinex" or a polyamide or even of a highly calendered paper.

The various layers of the material shown in FIG. 1. are laminated together by adhesive. In a typical case the whole material is prefabricated before being mounted on the wall, this also being effected by the use of an adhesive. In other cases the material might be prefabricated, with the exception of the wallpaper which would be hung after the rest of the material has been secured to the wall. The invention provides that it should be possibleto delaminate the multilayer material at one of the zones of adhesion. Typically this might be the zone between the wallpaper 73, 74, 75 etc. and the heating film 84, or between the heating film 84 and the dent-resisting layer 80. In the former case, the adhesive used between the wallpaper and the heating film could be an adhesive which is softenable by a solvent which can penetrate the wallpaper, while the surface layer of the heating film is insoluble in that solvent. Thus, if the wallpaper is penetrable by water, a water soluble adhesive may be used to fix the wallpaper to the waterinsoluble surface of the heating film. A water soluble adhesive such as that known under the trade mark Polycell may be used. The heating film of the invention is usually coated with a water-insoluble substance, for example a polyvinylacetate based copolymer, at least on the surface which is arranged to face the wallpaper; Provided the heating film was not penetrable by water, a water-soluble adhesive could be used between it and the layer 80, but if it is penetrable, a water-insoluble would be necessary between the heating film and the layer 80.

The adhesive used between the heating film 84 and the layer 80 could be one which softens at a temperature considerably higher than that developed by the heating film when it is in use, the adhesive used between the wallpaper and the heating film and between the layer 80 and the insulation 83 being of a character not affected by heat. Further back the adhesive would in any event be protected from heat by the insulation 83. By the term considerably higher temperature" is simply meant that the temperature is sufficiently higher than that developed by the heating film, even when temporarily overloaded for instantaneous space heating purposes, to avoid any risk of detachment or undue weakening of the bond during use of the heating film.

If the wallpaper is penetrable by water and is secured by a water-soluble adhesive e.g. (e.g.Polycell"), while the heating film 84 is secured to the layer 80 with a heat-softenable adhesive, (many suitable thermoplastic adhesives are commercially available, having a polyvinylacetate or other polymer base) by suitable choice of the agent used for instance damping by wetting (soaking) or using a heated roller, the wallpaper could be stripped from the heating film or the wallpaper and heating film together stripped from the layer 80.

These are only examples, since it may be desired to provide for stripping at some other zone of adhesion within the thickness of the multilayer material. In FIG. 1 the thermal insulating layer 83 is shown much thicker than the layer 77. Thus if the heating film 78 is brought into operation, heat will be much more rapidly transmitted towards the wall 76 than in the opposite direction towards the space. The film 78 thus serves as a wall heater, heat being stored in the wall. By suitable choice of the relative thickness and nature of the two thermal insulating layers the relationship between the heat dissipated in oppdsite directions from the film '78 can be predetermined.

The heating film 84 being backed by a thick layer of insulation 83 but on the other side only having the minor thermal insulation presented by the paper 86 and the wallpaper, when brought into use will dissipate .the major part of its heat directly into the space as radiated heat.

The provision of two heating films in the multilayer material enables heating to be effected according to various schemes to suit the type of installation in which the material is used and the temperature conditions met with. It will be desirable to provide for independent control of the two films and for the control to be adjusted differently in respect of at least one of the factors of timing, distribution of energy over the area bounding the enclosed space, the amount of energy and manner of dissipation.

FIG. 2 illustrates one very simple scheme for achieving such independent control with a different range of adjustment for one of the films from that of the other.

Here the one heater comprises two sections 78a, 78b permanently in series through an on and off switch 85 across the low voltage secondary winding of a transformer 86 supplied from conventional alternating current mains, while the other heater comprises two sections-84a, 84b which-can be connected in series or parallel across the secondary winding or be switched off altogether, by means of a switch 87. With the switch 87 in the position shown in solid lines, the two sections are connected in series, when it is moved over the to the left to the broken line position the two sections are connected in parallel, while in midposition the two sections are disconnected altogether. In addition to the switches 85, 87 there is a switch 88 which enables the supply to both heaters to be switched off, and a fuse 89 protecting the secondary circuit. It will be understood that the switches 85 and 87 will be controlled in accordance with the conditions, for example the switch 85 from a temperature sensing device and the switch 87 by a combined manual and time mechanism.

It is not essential that the multilayer material of the invention should be permanently fixed to a wall. Thus as shown in FIGS. 3 and 4 a rollable and therefore extendible multilayer material according to the invention is provided, having a decorative covering layer to form a decorative scroll, blind or curtain, which is supported in its coiled form FIG. 3, by an arm 181 attached to a wall 182 of the room to be heated. When it i is desired to use the material to heat the room it is extended until it covers the wall 182, as shown in FIG. 4. Its free end isv attached, by a spring clip 183, to a second arm 184. Electrical power is supplied to terminals attached to arms 181, 184 andthus the heating film 180 incorporated in the material emits heat to warm the room. Power cannot be supplied to the film until the free end of the film is connected to spring clip 183, and thus a safety device is incorporated in the system since the full power cannot be supplied until the material 180 is fully extended.

The material 180 may incorporate two heating films as in FIG. 1 or only a single such film and it may include an insulating layer between the heating film and the wall 182.

With material used in this way it will usually be stripping of the decorative material which is provided for by the invention, so that the latter can be replaced from time to time without af-,

fecting the rest of the multilayer material. Stripping can be ef fected and a new decorative layer applied with the material extended over the wall, notwithstanding that the material is not permanently fixed in this embodiment.

The rollable multilayer material may incorporate a flexible thermal insulating layer, the heat transmittance of which is adjustable. Thus as shown in FIGS.5 and 6 a thermal insulating layer 93 forms part of the multilayer material and is constituted by an elastic material having inflatable internal cavities 92 distributed over it, the inflation of which can be varied to adjust the overall thickness and consequently the heat transmittance of the layer of insulation. Thus FIG. 5 shows the cavities inflated much more than FIG. 6. These FIGS. also show the multilayer material extendible over the wall and suspended as in FIGS. 3 and 4 but it could also be used in a permanently extended form, even with the layer 93 fixed to the wall at the small zonesof contact indicated at 95 in FIG. 5 so as to interfere as little as possible with the possibility of variable inflation of the cavities 92.

This material may be controlled in accordance with the temperature at some point in the heated space, for example the surface temperature of thematerial. Thus as in FIG. 5, a thermostat 110 which senses the surface temperature incorporates a switch 111 which is .opened and closedas the temperature rises above or falls below a predetermined value and through a solenoid 112 regulates a valve 113 which connects the cavities 92 either to exhaust'or to an air supply 114, thus regulating the inflation of the cavities in accordance with the temperature.

This material can further be used for flooding a room with heat and subsequently reducing the heat supplied to the room by the heating film, say after an initial period of up to minutes. Thus as shown in FIG. 5a, the supply may be drawn from the conventional alternating current mains through a transformer 115 with a secondary winding in two sections 1161:, 11612 which by a switch 117 can be connected in series or parallel to provide a secondary voltage at 12 volts or 6 volts. During the initial period the supply is at 12 volts but at the end of the initial period, determined by an adjustable timing device such as a timing relay 118, combined with a solenoid having its core mechanically linked to the switch 117, the voltage to the material is reduced to 6 volts. Alternatively, with a constant power input to the heating film, the proportion of power radiated as heat into the room and conducted as heat into the wall may bereadily varied by inflating and deflating layer 93.=Thus layer 93. could be inflated during the initial period, thereby increasing the proportion of heat radiated into the room and decreasingthe proportion of heat conducted into the wall, and couldthen be deflated after the initial period, the timing device. in this case serving to control the valve 113.

The rollable extendible multilayer material of FIGS. 3 to 8 could be used as or on portable screens which may form temporary wall surfaces of a room' and the inflatable material may be used as the main component of a heatable wall of an inflatable dome, igloo, tent or other structure held in erected position by inflation, while a strong textile or other fabric constitutes the outer component of the wall. Temporary partitions may be provided with'collapsible'heating layers and the partitions could then replace the wall in the'arrangements of FIGS. 3 to 6.

The material of FIGS. 3 to 6 when extended over (or fixed to) the wall and with the heating film in use, as well as radiating heat into the space is also in direct heat exchange relationship with the neighboring wallsurface. When the inflation of the layer 93 is varied not only is the heat transmittance of the layer 93 thereby changed but the heating film is moved while it remains parallel to the neighboring wall surface, and even if the heat transmittance of the layer 93 were changed only negligibly or not at all, the movement of the film could vary the relationship between heat dissipated in opposite directions by the film. Such'a movement and variation in relationship of heat dissipated in opposite directions can also be achieved by omitting the cavities 92 and simply swinging the arms 184 to move the film towards or away from the wall.

In any of the above described embodiments, if the heating film embodies a metallic foil with the pattern of FIG. 7, the foil itself will be vapor-impermeable. The patterned foilcan be converted into a complete vapour barrier by closing the openings 101 by a vapour-impermeable flexible water-insoluble substance which is of relatively negligible electrical conductivity. The heating film will thenserve to prevent surface and interstitial condensation both when the heating film is switched on and when it is switched off, even if the other layers of the material are not impermeable to vapour. While the substance may be inserted in the openings as an independent operation in the production of the film, it is much simpler to use the adhesive by the aid of which the adhesive by the air of which the three layers of the film are laminated together for the purpose. Thus the adhesive may be a thermoplastic based on polyvinylacetate, or it may be an elastomeric adhesive such as neoprene, and is squeezed into the openings 101 during the laminating process.

Any of the various layers of the multilayer material may be of flame proof or fireproof material, thereby enhancing the fire resistant properties of the material.

The use of at least one thermal insulating layer as in all the above described embodiments, usually also assists sound insulation of the space, because the materials suitable for the purpose of thermal insulation are usually also efficient insulators for sound.

Iclaim:

l. A rollable multilayer'wall covering material for use in space heating comprising two electric resistance heating films extending throughout the material and means spacing said films apart, said spacing means including thermal insulation constituting the major thermal insulating layer in the material so that when the material is applied to a wall, one film when energized dissipates heat primarily into the space, and the other film when energized dissipates heat primarily into the wall, a thin decorative layer on the side which bounds thespace hung in strips with overlap between adjacent strips adequate to avoid gaps due to" contraction under operating conditions, and a porous thermal insulating layer at least between the heating films.

2. A rollable multilayer wall material according to claim 1 in which the two films are so connected that they can be independently controlled for dissipating heat into the space under conditions which can be adjusted differently in respect of at least one of the factors of timing, distribution of energy over the area bounding the enclosed space, amount of energy and manner of dissipation.

3. A rollable multilayer wall covering material according to claim 1 including a thin thermally insulating layer over that heating film which is nearer the wall when the material is applied to a wall.

4. A rollable multilayer wall covering material according to claim 1, the layers of which are laminated together at latest at the time of application to the wall, the material comprising at least three sections, the second section being a thin layer having two surfaces at which the first section and the third section respectively are normally adhered thereto, neither heating tion, the first section being undamaged by said agent, and the third section being penetrable by said agent.

'5. A rollable multilayer wall covering material according to claim 4 having more than one thin layer at which delamination is possible, the respective thin layers being constituted by adhesive which can be weakened by different agents so that the thin layers at which delamination is effected can be selected by choice of the agent used. v

6. A rollable multilayer wall covering material according to claim 4 in which the second section is constituted by an adhesive which softens at a temperature considerably higher than that developed by either heating film.

insoluble in and impenetrable by the solvent.

8. A rollable multilayer wall covering according to claim 7 in which the adhesive is a water-sensitive adhesive and the third section is water-permeable. 

